This is obviously not something that is useful to the average multiplex, although every serious museum, film festival, college film society, or art-house theatre will have the need to run 16mm film from time to time. Unfortunately, there aren't very many currently-available 16mm xenon projectors for these purposes, and those that are tend to be horribly expensive, often costing more than similarly equipped 35mm equipment.
Eiki makes one of the most common lines of 16mm projectors, ranging from small classroom models with tungsten bulbs, through the EX-9100, a 2kw xenon model with geneva movement. The EX-6100 is their 1kw xenon model. The unit includes a non-removable lamphouse (which can be aligned easily without tools), lamp and exciter power supplies, optical and mag preamps with 1/4" line output (XLR connectors would have been preferable, though), monitor speaker and amp (which is not sufficiently loud to be useful), and a 50w amplifier. Two machines may be connected with a separate changeover cable, or complete features may be run off of 6000' reels on one machine.
First, check out the film path:
The Eiki is very simple to thread, and, unlike most small projectors, uses separate sprockets before and after the soundhead, providing reduced wow and flutter and excellent overall sound quality; the Eiki is probably the best-sounding 16mm projector that I have ever heard, insofar as it is possible for a 16mm optical track to sound "good." The exciter lamp can be changed very easily. Mag sound is also supported, and alignment of both the optical and mag heads is very simple.
There is a scope lens bracket in front of the lens (there is no scope lens in the picture), which makes it easy to quickly and correctly position the scope lens without a lot of trial and error, which makes life easy for programs that include flat shorts and a scope feature. Unfortunately, this requires that you buy the expensive Eiki scope lens, instead of being properly sized to allow the use of a 35mm anamorphic attachment.
Other nice features include a mechanism to automatically drop the lamp current from a max of 50 amps down to about 30 amps when the motor is not running in order to (ostensibly) save lamp life, (mostly) easily accessible internal parts for quick repairs, and a motor-driven takeup, which ensures constant tension throughout the reel. The EX-6100 can be connected to a standard 30-amp 120vac outlet, and so does not require three-phase or 220v power.
So what's so wrong with this that I'm giving it a C+? Plenty! Although the on-screen picture is unquestionably big, bright, and steady and at times will rival the quality of 35mm (particularly with old B&W or dye-transfer prints), there are quite a few "mis-features" which would have been pretty easy to fix in the design process and which make this machine (at times) a royal pain to use.
For one thing, the machine is belt-driven, much like the Christie "gearless." This might not actually be such a bad thing, though, since it is unlikely that a 16mm projector would receive daily use, and it also allows the machine to work without much maintenance, which is particularly important in environments where it will be run by unskilled operators (museums, college film societies, etc.); on the other hand, a spare set of belts must be kept on hand at all times (though I've never seen one break, personally). The Eiki uses a two-tooth claw movement, just like the classroom projectors. The picture is steady, but film with torn perfs can tend to jump in the gate, and the loop-restore mechanism is quite useless. In general, this is not the machine to get if you plan to run film that is not in good condition.
The whole machine is controlled by pushbuttons on the operator side of the lamphouse. In theory, this would be a good idea, except that the implementation is quite poor. For example, the changeover mechanism is horribly designed, apparently by someone who didn't understand film. When the operator hits the "changeover" button on the incoming machine, there is a two-second delay while the lamp fires and the film begins moving before the changeover actually occurs. Even if the lamp and film are started manually (using the "lamp" and "forward" buttons), the delay cannot be avoided. Thus, the operator is forced to count seconds after the first cue mark, and hit the "changeover" button approximately one and a half seconds before the second cue.
Almost as bad is the fact that stopping the outgoing projector to remove the just-shown reel after each changeover requires hitting the green "power" button, which also shuts off the lamp (but not the blower or exciter, which are controlled by a master power switch). Thus, each reel change requires re-striking the lamp, which is not a particularly wonderful thing for lamp life, especially considering that many venues that run 16mm do so for the ever-decreasing degree of economy that it provides over 35mm.
Other complaints: there is no convenient way to run these projectors at silent speed, which is a problem since it is often easier to obtain good prints of silent films in 16mm than in 35mm. Similarly, there is no easy way to interlock these to a DA-88 machine or mag dubber (which would be useful for festivals). The hour meter runs continuously when the blower is running, even when the lamp is not struck. There is no inching knob; the projector can be advanced only with an electric pushbutton. It is possible to rewind the film on the machine itself, but the rewind function will not work if the failsafe function is engaged (which kind of makes sense, but has confused more than a few people). The film can be run in reverse at 24fps, but cannot be projected in reverse (so why bother including a reverse function at all?). There is no separate aperture plate which can be used to correct for visible keystone problems; if your screen is not sized perfectly or if the projector is slightly off-center in the auditorium (which would be common when used with 35mm equipment in a 3-machine booth), there is no easy way to correct this. The gate is of the swing-out type, which makes threading easy, but which also makes it all-too-easy to disturb the lens (and focus) when threading.
In short, I can't really say that this product is so wonderful that everyone should go out right now and buy one. It's decent, but I would expect better for a machine with a list price of $18,440. The whole thing just feels kind of "cheap" to me, and isn't worth that price. For not much more, the Kinoton or Elmo projectors would probably be a better choice. On the other hand, used EX-6100s can sometimes be had for about $5k, which isn't a bad deal. The big advantage of the EX-6100 over older (and probably superior) machines like the Filmo-arc and Eastman 25 is that it is a current model, and parts availability is not a problem.
Bottom line: If you need 16mm capability, you could do worse.